Improvement in sewing-machines



UNTTED STATES PATENT CFEIGE.

WILLIAM C. IICKERSGILL, OF- PROVIDENCE, RHODE ISLAND, ASSIGNOR TOPROVIDENCE TOOL COMPANY, OF SAME PLACE.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent No. 136,616, dated March1l, 1873.

To all whom it may concern:

Be it known that I, WILLIAM C. PreKERs- GILL, of the city and county ofProvidence,

is a full, clear, and exact description thereof.

The drawing exhibits an elevation of a sewing-machine with myimprovements. t

The machine in which I have embodied the several features of myinvention, and which is herein described, is believed by me to be animprovement on that class of machines in which the vibratory movement ofthe shuttlelever is obtained from abifurcated bar, which verticallyvibrates on a xed pivot and straddles or embraces between its arms arevolving cam mounted on the operating-shaft.

In the drawing, A represents the operatingshaft. B is an eccentric wheelset thereon. This eccentric gives a vibratory movement to therocker-shaft M, arranged in suitable bearings underneath the table ofthe machine, through vthe means of the link D, the lower end of suchlink being pivoted to the crank Fin said shaft M. At right angles withthe crank F, or nearly so, there is an upwardly-projecting arm, G,

. thel end of which is made into the form of a ball and engages with thestraddle-fork end of the shuttle-bar H, and imparts the necessaryvibratory movement to the latter towork the shuttle. With thisarrangement of the connections between the shuttle-lever and the sourceof motion no extreme nicety of construction is required or diliicultiesof adjustment exist in order to obtain the proper traverse of theshuttle.

A portion of my present improvement consists in the combination ofdevices for working the four-motion feed employed in this machine. Thisportion of my invention consists in the combination and arrangement ofthe devices for giving the vertically-reciprocatin g movement of thefeed-bar, and the arrangement and combination of devices for giving thehorizontal reciprocatory movement to thefeed-bar and regulating thelength of the stitch.

The rockshaft M, before referred to, is furnished with a toe, T, theface of which can be readily shaped so, as it vibrates with the shaft towhich it is attached, that the necessary upand-down movement can begiven to the feedlever 0, which is pivoted at its rear end, at N, to anarm keyed to the rock-shaft L, presently to be referred to. Afriction-roller, a, is set in the under face of the lever 0,' or in afootpiece, which roller rides on the face of the vibratin g toe T. Thisarrangement accomplishes simplicity of construction and easy adaptationofthe parts to each other. I is a constantly vibrating cam-face, made soby means of an eccentric, C, on the shaft A, and theconnecting-link E,the block to which such cam-face belongs being pivoted to a down-hanger,S. K is an arm, the hub of `which is fitted to slide on the shaft L, andwhich latter is hung in bearings in down-han gers underneath the surfaceof the cloth-plate or table and parallel therewith. A spline, b,connects such arm with the shaft L, and a roller, c, in the arm, is keptin constant contact with the cam-face vI by means of a coiled spring, d,which is attached at one end to a pin, e, projecting from the shaft L,and at the-other end to a fixed eye on the under surface of the table.The arm K can be moved to and fro on the shaft L by the operator so thatthe roller c shall bear upon any section of the cam-face I, and a clamp,R, secures the same at any xed point. N ow, the extent of vibration ofthe shaft L obviously depends upon the position of the roller c upon thecam-face I, and consequently the feed-bar O will have a longer orshorter extent of reciprocatory movement, correspondingly.

What I claim as my invention, and desire to secure by Letters Patent,is-= 1. The combination of devices for giving to the shuttle-lever ahorizontally vibrating move ment, and also for giving vertical movementto the feed-bar, the same consisting of the eccentric on the mainshaft,'its pitman or link D, and the vertically-vibrating bell-cranklever, connected with the shuttle-lever by means of a spheroidal tipembraced within a bifurcation, and operating a toe-cam below andadjacent to the feed-bar, substantially as dethe eccentrics B and (l,and the presser-arm scribed. K, made adjustable with relation to thecani- 2. The combination of the vibrating cam face, snlzstamtially` asand 'for the purposes ltence I, adjustable presser-arm Krediet-shaftspecified. Y Y .l v L, and feed-bar O, substantially as described. 4W.C. PICKERSGILL.

3. The combination, with the feed-bar, of Witnesses: v the vibrating toeT, the vibrating cam-face I, BENJ. F. THURST'ON, both of which arerespectively operated by I. KNIGHT.

